Mobile body



June 7, 1949. A. WOLF MOBILE BODY Filed Jan. 16, 1946 INVENTOR Abraho mU] BY ATTO R N EY Patented June 7, 1949 hair so stares her ear ore iceMBB'ILE BODY" Abraham-Wolf, Vineland,.-N., J.

Application'J'anuary' 16, 1M6; Serial No: (341}524? 2: (Elaimsa (CL.17-0--15 9) This invention relates to mobiiebo'diesadapted to travelthrough fluidmedia, suelras aircraft, marine vesselsand the like; andmore-particularly to improved-propeller structure therefor.

It is well'l znown that a part ofthe-resistance oiiered to the forwardmovementof airorait'employing propellers is d ue 'to' the compacted bodyof air which is built-up in the region immediately in. front of the huba-nd inner ends of-"the blades of thepropeHer'Whichradiate-from the hub;In the vicinity of. this region, thepropeller hasvory little, if any,propelling power. This is du'e" to the fact that the air in thisregionis not d riven rearwardly: by the rotating propeller; as is theair at a greater radial distancewoutwai dly' f 'rom the hub where: the:blades actu pon the air to impart rearward motion thereto; In" generalt.the same is also true of propeller driven. marine'vessels', thepropellers of which encounter similar resist"- ance by the Water. madehereto-fore to eliminate; or? at. least toimate rially reduce, thiscompacted body of fluid medium in front of the hub andvthe: regiomtherearound, but these have met with little success, so'far as I amaware.

The primary object of my. invention is: toz'provicle, in aircraft,marine vessels; and sirrrilarfm-obile bodies which'are designed to.travel through fluid media, an improved'propeller construction whichwill vary greatly reduce: the: aforemens ticned, compacted, fluid-body,and therefore. will greatly increase the ei'licien'cy of such: mobilebodies.

More particularlmit is an object: of my inventionto provide an improved;attachmentfor'pro pellers of mobile-bodies ofrthe type set forthabovewhich will be effective to increase t'he bite of the propeller blades inthe fluid medium in whichit operates to thereby increase the speed ofthe moving body for a. given power consumption, or, for a given speed,will require less power.

Another object of my invention is toprovid'e an improved attachmentforpropell'ersas afore said which can be applied readily to most existingpropellers.

Still another object of my invention is toprovide an improved propeller:structure foraircra-ft which will tend to lessenthe efi'ect'of headWind's by drilling through the air, so-t'o speak;

A further object of my invention is to provide an improved" propellerconstruction for" aircraft and the like which WilltendtvmifiimiZGdrifting, off course flying, and sud-den drops of the 'craft.

Still a further objector my invention isto pro vide an improvedpropeller construction asset Many." attempts: have: been 2 forthabove'whiclr will tend-'toreduee vibration of the rotating parts to aminimumit t'i fi ing to". increase the. life: of the driving! motortherefor.v

It is also; an. object of my invention: to;- ovide an. improved"attachment for propellers asi set forthrahoverwhich. is very simpleiinconstruction, econ'omicalrincost, and; highly efficient: inuseIirxaccordance with my invention, I provi'doeas ans. attachment to thepropeller on. the? tram; thereon and? for rotation; therewith, asubstana tiazlly conical member constructed: to: bore? through the fiuidimedium; as it were, an'dlltherehy overcome the compacted. bodynormally: misting in; thevfluidsmedium. in: front. of the-propellerhubregiom For this purpose, the conical. nose-pieceis provided: with aplurality of helicalgrooves. or channels? in its surface extendingfromits for ward; apex end'all. the way bach'to its base end againstwhich; the propeller blades: are disposed; Each groove terminates at therear surface of-orre of the propeller blades and: receives: and guidesastream: ot'ithe fluidmedium tangentially onto its associated blade. Thisbreaks up the compacted flfuidfi bad y and provides fluid atthe normallyinactive region of the propeller for the blad'es to bite into.Preferably, the base diameter and lengthroftlie conical nose-pieceisol-theorder ot one=third the diameter of the-circle described by theouter endsor tips ofthe propeller blades asthe propeller rotates. Asimilar n'o'se piece structure maybeemployed to= advantagein shells orother'siinilar explosive projectiles which are protected through air orwater.

The novel features that'I consider" character= is-tic-of my inventionare set'forth withparticua la-rity int-he appended claims. The inventionitself, however, both as toits organization and method-'ofoperation,aswell as ad'ditionalobj'ects and" advantages thereof; will best" beunderstood from the-f01lowingdescription, when read'incomnection withthe-"accompanying drawingirr which Figure" 1- isa frontelevationof'anaeroplane propeller provided'witha nose-piece attachment inaccordance withmy invention;

Figure 2 is a toppl'an' view thereof,

Figure 3-"isa 'rear' elevation thereof,

Figure-A" is an elevation of'the noserpiece. oi l igures'r-a asseerrfrom the base"end"thereof;-

Figure fi'is a View partly in section, ofthe stern of ashiphavingj a;propeller structure in accord; ance with'my invention, K

Figured is an enlarged; top plan view of... the propeilwstructure ofFigure 5,,and

Figure 7 is a fragmentary side elevation of an explosive shell having anose formed in accordance with my invention.

Referring more particularly to the drawing, wherein similar referencecharacters designate corresponding parts throughout, there is shown, inFigures 1-3, an aeroplane propeller havin a hub l which is adapted to besecured to a propeller shaft and from which radiate three suitablypitched blades 2 in known manner. Secured to the front of the propeller,as by screws 3, is a. substantially conical nose-piece 4 the base orlarger end of which is disposed against the blades and the body of whichextends forwardly of the propeller so that the apex end thereof is inadvance of the propeller in the direction of movement of the aeroplaneof which the propeller is a part. Preferably, the base end of thenose-piece 4 is formed with a central seat 5 for the reception of thehub l and with a plurality of radial slots 6 which extend outwardly fromthe central seat 5 each for the reception of one of the blades 2. Thepropeller is thus set into the base of the nosepiece 4 somewhat as bestseen in Figure 2.

The nose-piece 4 is formed in its conical surface with a plurality ofhelical grooves or channels T which extend from the apex end to the baseend thereof, there being as many grooves 1 as there are blades 2, andeach groove 1 being associated with a different blade. Preferably,although not necessarily, each groove 1 is of less than a complete orfull turn, as best seen in Figure 1, and preferably, also, each groovewidens gradually from the apex end to the base end of the nose-piece,each groove 1 merging into its associated blade 2 at the rear surfacethereof, as best seen at the center blade 2 in Figure 2.

The nose-piece 4- may be made of any suitable, non-corrosive, lightweight material so that it will not add any appreciable weight to theaeroplane. As the propeller and nose-piece rotate as a unit duringflight, the nose-piece bores into the air and each of the grooves 1receives and uides to the rear surface of its associated blade 2 astream of air. The several air streams are directed tangentially ontothe rear surfaces of their respective blades by reason of the fact thateach groove 1 merges thereinto as described above. In this way, thenormally compacted body of air in front of the hub l and the innerportions of the blades 2 is broken up and fed to the blades which arethen enabled to improve their bite in the air, since these innerportions of the blades are normally quite ineffective. I have foundthat, for optimum results, the base diameter and length of thenose-piece 4 should preferably be about equal and that each shouldpreferably be of the order of one-third of the diameter of the circledescribed by the outer ends of the blades 2. However, these proportionsmay be varied to a considerable extent depending upon the size and pitchof the blades, the depth and width of the grooves l, and so on.

In Figure 5, I have shown my invention applied to a ship 8 having apropeller shaft 9 to which the propeller represented by the blades [0 issecured. Here, the nose-piece 4 has an axial bore through which theshaft 9 passes and the nose-piece is also secured to the shaft 9, thebase end of the nose-piece being formed with radial seats for receptionof the blades ID in a manner similar to that described above. The apexend of the nose-piece faces the stern of the ship and the helicalgrooves I therein extend back to the base end where each merges into therear surface of its associated blade I0.

As the propeller Ill and its nose-piece 4 rotate, the grooves 1 directstreams of water tangentially onto the normally ineffective, inner, rearsurface regions of the blades l0, thereby increasing the bite of theblades ID in the water and improving the efficiency. This constructionis especially suited for electrically powered and turbine equipped shipsbecause of the smoothness of its water bite.

In Figure 7 I have shown an explosive shell H provided with a nose I2which is formed with a plurality of helical grooves in accordance withmy invention. The nose 12 may be of conventional ogival shape and thehelical grooves l therein extend from the tip or apex end of the nose tothe large end thereof, each being preferably about an eighth of a turnand substantially merging into the shell casing at the large end of thenose. When a conventional shell is fired from a cannon, for example, airpressure is built up at the nose of the shell and this retards theflight of the shell more or less. However, when a shell constructed inaccordance with my invention is fired, the helical grooves therein,which are turned in the same direction as the direction of rifiing,enable the shell to drill through the air and thereby overcome the airresistance. Hence, my improved shell will travel faster and will have amor powerful impact when it strikes a target. Moreover, a shellconstructed as above described is less subject to wind drift andtherefore can be fired with greater accuracy.

Although I have shown and described several forms of my invention, itwill undoubtedly be apparent to those skilled in the art that many otherforms thereof, as well as variations in those described, are possiblewithin the spirit of my invention. I therefore do not wish to be limitedexcept insofar as is made necessary by the prior art and by the spiritof the appended claims.

I claim as my invention:

1. In a vehicle adapted to move through a fluid medium and including arotar ropeller for propelling said vehicle through said medium, anose-piece comprising a substantially conical member mounted in advanceof said propeller on an axis coincident with the axis of rotation ofsaid propeller, said member being rotatable with said propeller andhaving a plurality of circumferentially distributed, helical grooves inthe surface thereof each extending from its apex end to its base end,the number of said grooves being equal to the number of blades in saidpropeller, each of said grooves being associated with and terminating atthe rear face of a separate one of said blades, said grooves beingadapted to receive and guide therealong to the rear of said bladesstreams of said medium as said propeller rotates to advance said vehiclethrough said medium, the base end of said nose-piece being provided witha plurality of seats, one for each of said blades, said nose-piece beingdisposed against said propeller with the blades thereof received in saidseats, and the base end of each of said grooves being positioned todirect tangentially onto the rear surface of the blade associatedtherewith the stream of said medium guided thereby.

2. In a vehicle adapted to move through a fluid medium and including arotary propeller for propelling said vehicle through said medium, saidpropeller including a hub and a plurality of blades radiating outwardlyfrom said hub, a

nose-piece comprising a substantially conical member the base end ofwhich is provided with a central seat for said hub and a plurality ofblade seats extending radially outwardly from said central seat, saidnose-piece being mounted in advance of and against said propeller on anaxis coincident with the axis of rotation of said propeller and withsaid hub disposed in said central seat and a blade in each of said bladeseats, said member being rotatable with said propeller and having aplurality of circumferentially distributed, helical grooves in thesurface thereof each extending from its apex end to its base end, thenumber of said grooves being equal in number to the number of saidblades in said propeller, each of said grooves being associated with andterminating at the rear face of a separate one of said blades, saidgrooves being adapted to receive and to guide therealong to the rear ofsaid blades streams of said medium as said propeller rotates to advancesaid vehicle through said medium, the base end of each of said groovesbeing so positioned as to direct tangentially onto the rear surface ofthe blade associated therewith the stream of said medium guided thereby.

ABRAHAM WOLF.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,067,410 Newnham Jan. 12, 1937FOREIGN PATENTS Number Country Date 332,089 Great Britain July 17, 1930

